1. Technical Field
The present invention relates generally to imaging devices and more particularly to a device that aides placement and ensures accurate retention of documents on a platen of a flatbed imaging device during an imaging process.
2. Background Art
Flatbed imaging devices including electrostatic and electronic document scanners and copiers as well as multi-function peripherals typically require a face-down placement of a document upon a transparent platen. An imaging assembly is typically positioned below the platen and is configured to obtain digital image data representative of an image represented on a sheet document. A transport assembly transports the imaging assembly in a plane substantially parallel to the plane of the platen. Image data includes data relating to the position and alignment of the document on the platen.
Flatbed imaging devices typically include a hinged platen cover that serves several purposes. The platen cover may serve both as a weight to hold a document as flat as possible and as an appropriately colored background for a document that does not require the entire functional area of the platen. Additionally, the platen cover may include a document feeding mechanism for automatically feeding a document onto the platen for automated multiple-document imaging.
A platen including a larger functional surface allows for imaging a wider range of original document, but an oversized platen may also present alignment problems when a user places curled, distorted, odd-shaped, small, multiple, or lightweight document on the platen. Curled, distorted, odd-shaped, small, multiple, or lightweight originals shift out of position easily.
Closing and opening the platen cover may exacerbate the problem. Air turbulence caused by relative movement of the two large flat planes of the platen and the platen cover can easily shift the position of the original document, whether during closing the platen cover for imaging or during opening for adjustment of the originals. This problem is particularly evident when imaging curled items like thermal facsimile papers, lightweight document such as receipts, or multiple smaller originals such as photographs or checks (see FIGS. 1 through 3).
Consequently, accurately positioning any document other than the most common sizes of originals requires tedious care and sometimes multiple readjustments to obtain a single usable image. This problem can result in inaccurate imaging, waste of operator time, waste of resources, and undue wear and tear on the imaging device.
Therefore, it may be advantageous to provide a simple and low-cost device that will easily capture any assortment or single piece of document, whether curled, distorted, odd-shaped, small, multiple, or lightweight, securely against the imaging platen throughout the manual placement, imaging, and readjustment of the original document and the opening and closing of the platen cover. It may also be advantageous to provide a device that automatically articulates to provide ease of operation. Additionally, there may be advantage in preserving an existing alignment of the document when the platen cover is opened for adjustment to the position of the document. It may also be of advantage to provide a device that incorporates an indexing device to aid in more precise alignment of original documents. It may also be advantageous to allow manipulation of the platen cover, capturing device, and document with only one hand, allowing ease of operation and one-handed operation. There may also be advantage found in allowing the platen cover to stay in any one of multiple tactile positions while the document and capturing device are manipulated.